Frogs, and their Contributions to Science. 127 



by means of the skin. He would die as certainly if his 

 skin were covered by viscid oil or varnish, as if his mouth 

 were held open, and in either case it would be death by 

 suffocation. 



Behind the ear of the male frog, for they alone are 

 provided with the apparatus, there is a membranous sac 

 into which the air is forced as into a bladder by the action 

 of the muscles of the throat and abdomen. On its pas- 

 sage inwards, not outwards over the tongue, it gives rise 

 to the peculiar croak, or croassement, as the French have 

 it, of the frog. Aristophanes, in one of his comedies, speaks 

 offrogsasthe song living race, the marshy offspring of 

 the fountains, and tried to express the chanting of their 

 varied watery choral music amid the noise of burst- 

 ing bubbles, by the Greek words B^£xsxsx£xoaxoaf-xoa|. There 

 are three different sounds emitted by the frog, as I have 

 noticed them, a kind of wooing, muttering on the part of 

 the male in the spring, the regular orthodox croak, and a 

 cry of agony or pain which I have heard him utter while 

 being swallowed by the snake. There is a popular mis- 

 apprehension in regard to these sounds, I think, which 

 confounds the long monotonous roll of the toad, and the 

 sharp cry of the newt, with those of the frog. It is, b} ? no 

 means an unpleasant thing, however, of a warm spring 

 evening to listen to the lively music of a densely popu- 

 lated frog swamp. The continuous clatter of a thousand 

 croaking throats rising and falling in intensity, accompanied 

 perhaps by the deep bass of some lonely rana pipiens, or 

 the plaintive cadence of the sluggish toad, or the shrill 

 piping of the little water newt, make up, if listened to 

 aright, a veritable concord of sweet sounds. 



The first notes of the frog in spring are pleasant, 

 through association. Like those of the robin or blue bird 

 they are listened to as the harbingers of sunny days, and 

 budding flowers, and a new life. It is a common saying 



